Sure, the right lineup is important—including making the proper skincare routine transition—but first, it’s important to understand what dry skin is in order to combat it. Since colder weather is rapidly approaching, we enlisted some top dermatologists to find out how best to prepare for the winter skin storm forecast ahead.

What is the difference between dry and dehydrated skin?

Dry skin is often misunderstood. To put things simply, dryness refers to a skin type, and dehydration refers to a skin condition. “When you have dry skin, your face has fewer oil-producing glands; therefore less sebum is present,” says Debra Jaliman, MD, a board-certified dermatologist in New York City. “Dehydrated skin is a condition when your skin lacks water, as opposed to an impaired skin barrier.” People with dehydrated skin don’t necessarily have dry skin—it could be oily, combination, or normal skin that is simply lacking hydration. According to Shari Marchbein, MD, a board-certified dermatologist in New York City, dry skin sufferers need treatments geared towards repairing the skin barrier. “You’ll always want to use a gentle cleanser and avoid stripping soaps, in addition to moisturizing within 60 seconds of showering with a ceramide-rich moisturizer,” she says. When dealing with dehydrated skin, Dr. Marchbein recommends using humectants to attract and bind water molecules. “Increasing the water content of the skin is extremely important when dealing with dehydrated skin. They can draw water to the skin from the environment and enhance water absorption from the top layer of the skin,” she says.

What causes dry skin?

We live in a ruthless world of dry skin culprits. Cold air holds less moisture, so a dip in the temperature is one factor. “We need to switch up our skincare routine in the winter just as we would our wardrobe for the change of seasons,” says Dr. Marchbein. “Humidity levels in the air drop and this causes the skin to leach water back into the environment, making it dry. Couple this with long hot showers, not using appropriate moisturizers (or applying at the wrong time), and dry heat in most homes, and it’s a recipe for disaster.” Other sebum sappers? Lifestyle changes—including excess alcohol consumption, medications that affect hormones, and a poor diet—are all factors that lead to skin dryness. Overuse of anti-aging products that include acids or retinol can be very drying to the skin, adds Dr. Jaliman.

What ingredients should you look for?

“There are three musts: humectants, occlusives, and emollients,” says Neal Schultz, MD, a board-certified dermatologist in New York City and founder of DermTV.com. Humectants work by extracting water molecules from the air and pulling them into the skin’s surface. Popular humectant ingredients you may see include ceramides, alpha-hydroxy acids (lactic acid), sorbitol, glycerin, and hyaluronic acid. Occlusives serve as a physical barrier to help trap water in and prevent moisture loss from the skin’s surface. According to Dr. Schultz, common occlusive agents include silicone, dimethicone, lanolin, and white petrolatum. Lastly, emollients smooth over the skin and increase the rate of skin barrier restoration. Keep an eye out for lipids and oils, colloidal oatmeal, shea butter, and isopropyl palmitate. Retinol is also a miracle worker for rough texture—when done right. Used correctly, it will easily become your favorite Benjamin Button product. But when used incorrectly, your dry skin might be paired with major redness and irritation. If you are getting dry from using retinoids, Dr. Marchbein suggests using the sandwich technique: “After washing your face, apply a layer of moisturizing cream, then apply a pea sized amount of retinoid and then another layer of moisturizer on top. Studies have shown that this base layer of moisturizer does not dilute or reduce the efficacy of the retinoid, in addition to helping with tolerability.”

How can you prevent dry skin?

Counterintuitive as it may seem, you should start with a gentle scrub. “Without proper exfoliation, your moisturizer can’t penetrate and doesn’t do its job,” says Dr. Schultz. Once a week, in the shower, use one containing lactic acid. It dissolves dead cells and acts as a humectant. Skip formulas with sharp grains, like walnut shells, which can be too abrasive. As a rule of thumb, keep showers cool and short. This part is important, says Dr. Marchbein: “Always moisturize at least once a day, within 60 seconds of coming out of the shower, while you are still damp. Your pores are open and products will absorb more efficiently.” She also notes that the best moisturizers have a combination of emollients and humectants. “One of my favorite moisturizers containing glycerin is Vaseline Intensive Care Advanced Repair (with petroleum jelly and glycerin).” Another tip? Get a humidifier. “I like to compare it to drying a wet towel in muggy weather. No matter how long it sits there, it won’t completely dry because of the moisture in the air,” says Ling Chan, an aesthetician in New York City and founder of Ling Skincare. And in the case of your skin, that’s a good thing.

When is dry skin something more?

Flaking and feeling “tight” are normal symptoms of dryness. But if they’re accompanied by redness, swelling, excessive itchiness, or crusting, you should consult your dermatologist. It could be contact dermatitis, eczema, or psoriasis, all things that can be mistaken for dry skin," says Dr. Jaliman. Either way, your doctor can help treat it.